Use of 18O, 2H and 15N to identify nitrate contamination of groundwater in a wastewater irrigated field near the city of Shijiazhuang, China
Use of 18O, 2H and 15N to identify nitrate contamination of groundwater in a wastewater irrigated field near the city of Shijiazhuang, China
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DOI：
10.1016/j.jhydrol.2005.11.007
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发表时间：
2006-07-15
影响因子：
6.4
通讯作者：
Yu, Jingjie
中科院分区：
文献类型：
--
作者：
Chen, Jianyao;Tang, Changyuan;Yu, Jingjie
早在1958年，中国石家庄郊区就开始了污水灌溉。这导致地下水被硝酸盐污染，深度约为100米，平均浓度为40毫克NO3-/升。该地区的年平均污水灌溉量约为430 mm，与周边地区相比，地下水位相对稳定，没有使用过污水。根据δ O-18和Cl-的线性关系，发现废水和老地下水虽然成分不同，但混合良好。废水含有相对较高的氯离子，但没有检测到硝酸盐。Δ N-15在千分之7-11的范围内占主导地位（参考大气N-2标准），证实了受污染地下水中存在的硝酸盐来自废水。然后用硝酸盐作为示踪剂粗略估计地下水运动速率，得出垂直速率为2.0-2.5米/年，水平速率为41.8-62.5米/年。反硝化作用可以发生在一个区域2公里的废水运河，其中的分数从废水的贡献计算为76%。应提出对废水的健康关切。灌溉，这是中国主要城市郊区的常见做法，特别是在干旱和半干旱地区。(c)2005 Elsevier B. V.保留所有权利。
Wastewater irrigation was initiated as early as 1958 in the suburb of Shijiazhuang, China. This has resulted in groundwater becoming contaminated by nitrate to a depth of about 100 m with an average concentration of 40 mg NO3-/L. The annual average irrigation rate of wastewater in this area is about 430 mm, and the water table is relatively stable in contrast to the surrounding area, where no wastewater has been used. Although different in composition, wastewater and old groundwater are found to be well mixed based on the linearity of delta O-18 and Cl-. Wastewater has relatively high Cl-, but has no detectable nitrate. Dominance of delta N-15 in the range of 7-11 parts per thousand AIR (referred to atmospheric N-2 standard) confirms that the nitrate present in contaminated groundwater originates from the wastewater. Nitrate was then used as a tracer to estimate roughly groundwater movement rates, yielding a vertical rate of 2.0-2.5 m/y and a horizontal rate of 41.8-62.5 m/y. Denitrification could occur in a zone 2 km from the wastewater canal, in which the fraction contributed from wastewater was calculated to be 76%. Health concerns should be raised regarding wastewater. irrigation, which is a common practice in the suburbs of principal cities of China, especially in and and semi-arid regions. (c) 2005 Elsevier B.V. All rights reserved.